Good to meet you, Mark. Assuming you are right handed--your left hand chords and your right hand picks/strums--the following stuff may be helpful.

Unless you are in a single drop D (a tuning in which the bass E string is tuned down one tone (that is it goes from E down to D)), the Dmaj7 is done thus

X00222

The X means don't play the string, the 0 means it is left open, and the 2 means you fret that string at the second fret.

The usefulness of the drop D breezy plays it in will come clear after you use it for a while. However, it will eventually require the use of your chord-hand thumb (with the A chord for example). The chord would look like

202220 or 20222X with the thumb doing the 2 on the bass string.

Double drop D means both the bass and treble E strings are tuned down one tone--or from E to D. That becomes a different animal and might best be left alone for a while. I wish you every success with the guitar.

############################3

You shouldn't have mentioned being a drummer. It's kinda like saying you play banjo. Opens you up to all kinds of abuse.